Anticholinergic agents are believed to inhibit vagally-mediated reflexes by blocking acetylcholine at the cholinergic receptor. Anticholinergic agents are also believed to inhibit secretions of the serous and sero-mucous glands of the nasal mucosa. Anticholinergic agents for the treatment or control of respiratory disorders include tiotropium, oxitropium, ipratropium, glycopyrrolate, aclidinium, and salts thereof.
One known anticholinergic agent is tiotropium bromide, the chemical name of which is (1α, 2ß, 4ß, 5α, 7ß)-7-[(hydroxydi-2-thienylacetyl) oxy]-9, 9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.02, 4] nonane bromide monohydrate. Tiotropium bromide is commercially marketed in the United States by Boehringer Ingelheim Pharmaceuticals, Inc. as SPIRIVA® capsules containing lactose and 18 μg tiotropium (equivalent to 22.5 μg tiotropium bromide monohydrate) and inhalation solution SPIRIVA® RESPIMAT containing tiotropium bromide, water for injection, edetate disodium, benzalkonium chloride and hydrochloric acid. Tiotropium bromide is indicated for the maintenance treatment of bronchospasm associated with COPD and for reducing COPD exacerbations.
US 2004/0019073 discloses an aqueous inhalation solution comprising tiotropium and the preservative benzalkonium chloride.
Inhalation solutions generally contain preservatives such as benzalkonium chloride. Frequent exposure to low concentrations of benzalkonium chloride may lead to adverse effects. Some studies (Beasley et al., 1987, British Medical Journal, Vol 294, 1197-1198; Beasley et al., 1988, Br. J. Clin. Pharmac. 25, 283-287; Miszkiel et al., 1988, Br. J. Clin. Pharmac. 25, 157-163) also suggest that repeated use of COPD treatments with benzalkonium chloride may result in paradoxic bronchoconstriction, as benzalkonium chloride has bronchoconstrictor properties 7.4 times less potent than histamine. Moreover, exposure to benzalkonium chloride may lead to occupational asthma and may also cause dose-dependent bronchoconstriction.
Treatments for COPD often come in multiple dosage units and must be diluted to specific concentrations suitable for treating patients, or be directly delivered with the help of a costly and complicated device. This poses several problems while preparing the final dose and/or device for delivery. For example, COPD treatments requiring administration of a single dose unit from multiple dosage units sometimes lack proper mixing or diluting instructions, or the instructions for preparing and using the COPD treatment may be hard to follow or can be easily lost. Of even greater concern is haphazard diluting or mixing of COPD medications, which can result in administering the wrong dosage. This could be especially harmful for patients those are less tolerant to higher dosages of asthma medications. Incorrect mixing can also result in treatment failure such that additional medical attention is required, thereby increasing the time, expense and personnel costs associated with therapy.
There is, therefore, a need for an improved inhalation solution, system, kit and method for relieving symptoms associated with COPD.